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On Bardina and Approximate Deconvolution Models

Roger Lewandowski

Séminaire Laurent Schwartz — EDP et applications

We first outline the procedure of averaging the incompressible Navier-Stokes equations when the flow is turbulent for various type of filters. We introduce the turbulence model called Bardina’s model, for which we are able to prove existence and uniqueness of a distributional solution. In order to reconstruct some of the flow frequencies that are underestimated by Bardina’s model, we next introduce the approximate deconvolution model (ADM). We prove existence and uniqueness of a “regular weak solution”...

Impact of the variations of the mixing length in a first order turbulent closure system

Françoise BrossierRoger Lewandowski — 2002

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

This paper is devoted to the study of a turbulent circulation model. Equations are derived from the “Navier-Stokes turbulent kinetic energy” system. Some simplifications are performed but attention is focused on non linearities linked to turbulent eddy viscosity ν t . The mixing length acts as a parameter which controls the turbulent part in ν t . The main theoretical results that we have obtained concern the uniqueness of the solution for bounded eddy viscosities and small values of and its asymptotic...

Impact of the variations of the mixing length in a first order turbulent closure system

Françoise BrossierRoger Lewandowski — 2010

ESAIM: Mathematical Modelling and Numerical Analysis

This paper is devoted to the study of a turbulent circulation model. Equations are derived from the “Navier-Stokes turbulent kinetic energy” system. Some simplifications are performed but attention is focused on non linearities linked to turbulent eddy viscosity  ν t . The mixing length acts as a parameter which controls the turbulent part in ν t . The main theoretical results that we have obtained concern the uniqueness of the solution for bounded eddy viscosities and small values of and its asymptotic...

On evolutionary Navier-Stokes-Fourier type systems in three spatial dimensions

Miroslav BulíčekRoger LewandowskiJosef Málek — 2011

Commentationes Mathematicae Universitatis Carolinae

In this paper, we establish the large-data and long-time existence of a suitable weak solution to an initial and boundary value problem driven by a system of partial differential equations consisting of the Navier-Stokes equations with the viscosity ν polynomially increasing with a scalar quantity k that evolves according to an evolutionary convection diffusion equation with the right hand side ν ( k ) | 𝖣 ( v ) | 2 that is merely L 1 -integrable over space and time. We also formulate a conjecture concerning regularity...

Analysis of the hydrostatic approximation in oceanography with compression term

Tomás Chacón RebolloRoger LewandowskiEliseo Chacón Vera — 2010

ESAIM: Mathematical Modelling and Numerical Analysis

The hydrostatic approximation of the incompressible 3D stationary Navier-Stokes equations is widely used in oceanography and other applied sciences. It appears through a limit process due to the anisotropy of the domain in use, an ocean, and it is usually studied as such. We consider in this paper an equivalent formulation to this hydrostatic approximation that includes Coriolis force and an additional pressure term that comes from taking into account the pressure in the state equation for...

Analysis of the hydrostatic approximation in oceanography with compression term

Tomás Chacón RebolloRoger LewandowskiEliseo Chacón Vera — 2010

ESAIM: Mathematical Modelling and Numerical Analysis

The hydrostatic approximation of the incompressible 3D stationary Navier-Stokes equations is widely used in oceanography and other applied sciences. It appears through a limit process due to the anisotropy of the domain in use, an ocean, and it is usually studied as such. We consider in this paper an equivalent formulation to this hydrostatic approximation that includes Coriolis force and an additional pressure term that comes from taking into account the pressure in the state equation for...

Numerical modelling of algebraic closure models of oceanic turbulent mixing layers

Anne-Claire BennisTomas Chacón RebolloMacarena Gómez MármolRoger Lewandowski — 2010

ESAIM: Mathematical Modelling and Numerical Analysis

We introduce in this paper some elements for the mathematical and numerical analysis of algebraic turbulence models for oceanic surface mixing layers. In these models the turbulent diffusions are parameterized by means of the gradient Richardson number, that measures the balance between stabilizing buoyancy forces and destabilizing shearing forces. We analyze the existence and linear exponential asymptotic stability of continuous and discrete equilibria states. We also analyze the well-posedness...

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